6 Minute Solutions Problem 28

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MrMike

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I understand the problem and the solution using the Hardy Cross Method except for a negative sign in the solution.

correction formula = -sigma k*Q / n * sigma absolute of k *Q

In the solution it is assumed all flows in the clockwise direction are positive.

For the numerator for the correction formula, the solution reads -{(63*1.25^2)-(382*0.72^2)-*(35*0.75^2)}. The whole sum of k*Q should be taken against the negative sign but shouldn't the first flow value of 1.25 cfs be taken as a negative as well. The flows for the other two pipe branches of 0.75 cfs are both consider negative. I don't think I explained that well but any help would be appreciated. You will have to look at the book for an illustration of the pipe network.

 
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